G6, G5 and 5G: Everything from Mobile World Congress press day

The show floor for Mobile World Congress, the world's biggest showcase for wireless technology and mobile devices, doesn't officially open until Monday. But like all good trade shows, "day zero" is press conference day.

The elephant in the room at the 2017 show is the phone that isn't here: the Galaxy S8. But Samsung teased the phone at the end of its otherwise sedate Sunday press conference, confirming the rumors that the phone would indeed be unveiled on March 29 in New York City.

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LG G6 is water-resistant, with a whole lotta screen

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With no Galaxy phone on deck, the LG G6 was the big dog of the day. The Korean company's 2017 flagship phone offers a nice big 5.7-inch screen with an unusually tall 18:9 aspect ratio (instead of the 16:9 standard). It's the first phone with support for Dolby Vision HDR, which could mean better-looking images, too. It's fully waterproof, and has a dual-lens camera with some nifty photo tricks, too. Early downsides? The G6 doesn't retain the LG G5's swappable batteries -- a feature that's largely going the way of the dodo -- and its Qualcomm Snapdragon 821 processor is effectively a 2016 chip that's a step behind the latest and greatest 835 we'll see in upcoming phones.

Yes, Mobile World Congress has a bit of a retro flavor this year. The show kicked off on Saturday night with the introduction of the BlackBerry KeyOne, a full-on Android-powered keyboard phone (produced by China's TCL) that recalls company's pre-iPhone glory days.

Not to be outdone, old-timer Nokia (or, at least, licensee HMD Global) showed off three Android phones of its own. More enticing, however, was its 3310 "feature phone," a non-smartphone based on a 1990s classic that makes phone calls and sends texts -- and not very much else. But will this revived Nokia finally come forward with a real game-changing phone? The jury's still out on that one.

Oh, and remember when Nokia bought Withings, the French health and wearable company? That brand is going away, and those products will get the Nokia brand going forward.

Samsung ended press day with a fairly sleepy event. Two new tablets -- one Android and one Windows -- dominated the proceedings, and a new Gear VR headset with a bundled controller made an appearance, too. But Samsung did end the show with a video teaser for that missing Galaxy S8: Expect to see it unveiled on March 29 in New York City.

Plenty of other headlines were coming out of Barcelona today, too. Next-generation 5G wireless was highlighted at nearly every press conference -- it looks like the first products may hit even sooner than originally thought, whether or not standards are ready. Huawei showed off its latest phones and wearables, too.

And Google dropped some big news: Its voice-activated Google Assistant, currently only on Google's Pixel phones and slated for the LG G6, will actually be available on nearly every Android 6.0 and later phones (in certain territories) as soon as this week. That's a free upgrade for millions of mobile users.